In an ink jet recording device for adjusting supply pressure of ink to a recording head according to a water head difference, when an ink liquid surface in an ink tank fluctuates according to ink consumption, ink supply pressure also fluctuates accordingly. Particularly in industrial ink jet recording devices in which continuous duty is required, such a fluctuation in the ink supply pressure caused by ink consumption is not desirable. Therefore, in ink jet recording devices that can adjust supply pressure of liquid to recording heads, technique for repressing a fluctuation in the ink supply pressure caused by ink consumption is required.
Patent Document 1 describes an ink jet recording device in which a back pressure tank which is connected to a recording head and whose liquid level is kept constant by supplying ink from a main tank according to ink consumption is provided between the recording head and the main tank in the ink jet recording device, and a position of the back pressure tank is adjusted in a height direction so that a position water head of the liquid level of the back pressure tank with respect to the recording head is adjustable.